Is 20720 a prime number?

No. 20720 is composite — it has more than 2 divisors (it has 40).

Divisors of 20720: All 40 Factors

Q: What are the divisors of 20720?

The divisors (factors) of 20720 are 1, 2, 4, 5, 7, 8, 10, 14, 16, 20, 28, 35, 37, 40, 56, 70, 74, 80, 112, 140, 148, 185, 259, 280, 296, 370, 518, 560, 592, 740, 1036, 1295, 1480, 2072, 2590, 2960, 4144, 5180, 10360, 20720.

Q: What is the sum of the divisors of 20720?

The sum is 1 + 2 + 4 + 5 + 7 + 8 + 10 + 14 + 16 + 20 + 28 + 35 + 37 + 40 + 56 + 70 + 74 + 80 + 112 + 140 + 148 + 185 + 259 + 280 + 296 + 370 + 518 + 560 + 592 + 740 + 1036 + 1295 + 1480 + 2072 + 2590 + 2960 + 4144 + 5180 + 10360 + 20720 = 56544.

Quick Answer

20720 has 40 divisors (factors): 1, 2, 4, 5, 7, 8, 10, 14, 16, 20, 28, 35, 37, 40, 56, 70, 74, 80, 112, 140, 148, 185, 259, 280, 296, 370, 518, 560, 592, 740, 1036, 1295, 1480, 2072, 2590, 2960, 4144, 5180, 10360, 20720.

Sum: 56544.

Divisors (Factors) Calculator

Divisors Multiples Prime Factoriz. GCF LCM

Use the calculator above to find all divisors (also called factors) of any positive integer up to 4,782,969. Beyond the divisor list, this tool also shows divisor pairs, the sum and count of divisors, prime factorization, and number properties (prime, perfect square, perfect number).

All Divisors of 20720

The number 20720 has 40 divisors:

1, 2, 4, 5, 7, 8, 10, 14, 16, 20, 28, 35, 37, 40, 56, 70, 74, 80, 112, 140, 148, 185, 259, 280, 296, 370, 518, 560, 592, 740, 1036, 1295, 1480, 2072, 2590, 2960, 4144, 5180, 10360, 20720

Divisor Pairs of 20720

Each pair multiplies to 20720:

Factor 1	×	Factor 2	=	Product
1	×	20720	=	20720
2	×	10360	=	20720
4	×	5180	=	20720
5	×	4144	=	20720
7	×	2960	=	20720
8	×	2590	=	20720
10	×	2072	=	20720
14	×	1480	=	20720
16	×	1295	=	20720
20	×	1036	=	20720
28	×	740	=	20720
35	×	592	=	20720
37	×	560	=	20720
40	×	518	=	20720
56	×	370	=	20720
70	×	296	=	20720
74	×	280	=	20720
80	×	259	=	20720
112	×	185	=	20720
140	×	148	=	20720

Number of Divisors

The number 20720 has 40 divisors, written as τ(20720) = 40 in number theory.

Sum of Divisors

σ(20720) = 1 + 2 + 4 + 5 + 7 + 8 + 10 + 14 + 16 + 20 + 28 + 35 + 37 + 40 + 56 + 70 + 74 + 80 + 112 + 140 + 148 + 185 + 259 + 280 + 296 + 370 + 518 + 560 + 592 + 740 + 1036 + 1295 + 1480 + 2072 + 2590 + 2960 + 4144 + 5180 + 10360 + 20720 = 56544

Prime Factorization of 20720

See the full prime factorization calculator →

Properties of 20720

20720 is composite.
20720 is not a perfect square.
Number of divisors: 40.
Sum of divisors: 56544.

Common Divisors with Another Number?

Looking for the divisors that 20720 shares with another number? Use our Greatest Common Factor (GCF) calculator — it finds all common divisors and the largest one.

Step-by-Step: How to Find the Divisors of 20720

An efficient way to find divisors uses the complementary pair trick: check each integer i from 1 to √20720 ≈ 143.94. If i divides 20720, then both i and 20720/i are divisors.

1 divides 20720 (20720 ÷ 1 = 20720) → pair (1, 20720)
2 divides 20720 (20720 ÷ 2 = 10360) → pair (2, 10360)
4 divides 20720 (20720 ÷ 4 = 5180) → pair (4, 5180)
5 divides 20720 (20720 ÷ 5 = 4144) → pair (5, 4144)
7 divides 20720 (20720 ÷ 7 = 2960) → pair (7, 2960)
8 divides 20720 (20720 ÷ 8 = 2590) → pair (8, 2590)
10 divides 20720 (20720 ÷ 10 = 2072) → pair (10, 2072)
14 divides 20720 (20720 ÷ 14 = 1480) → pair (14, 1480)
16 divides 20720 (20720 ÷ 16 = 1295) → pair (16, 1295)
20 divides 20720 (20720 ÷ 20 = 1036) → pair (20, 1036)
28 divides 20720 (20720 ÷ 28 = 740) → pair (28, 740)
35 divides 20720 (20720 ÷ 35 = 592) → pair (35, 592)
37 divides 20720 (20720 ÷ 37 = 560) → pair (37, 560)
40 divides 20720 (20720 ÷ 40 = 518) → pair (40, 518)
56 divides 20720 (20720 ÷ 56 = 370) → pair (56, 370)
70 divides 20720 (20720 ÷ 70 = 296) → pair (70, 296)
74 divides 20720 (20720 ÷ 74 = 280) → pair (74, 280)
80 divides 20720 (20720 ÷ 80 = 259) → pair (80, 259)
112 divides 20720 (20720 ÷ 112 = 185) → pair (112, 185)
140 divides 20720 (20720 ÷ 140 = 148) → pair (140, 148)
Collect all unique values: {1, 2, 4, 5, 7, 8, 10, 14, 16, 20, 28, 35, 37, 40, 56, 70, 74, 80, 112, 140, 148, 185, 259, 280, 296, 370, 518, 560, 592, 740, 1036, 1295, 1480, 2072, 2590, 2960, 4144, 5180, 10360, 20720} — total 40 divisors.
Sum: 1 + 2 + 4 + 5 + 7 + 8 + 10 + 14 + 16 + 20 + 28 + 35 + 37 + 40 + 56 + 70 + 74 + 80 + 112 + 140 + 148 + 185 + 259 + 280 + 296 + 370 + 518 + 560 + 592 + 740 + 1036 + 1295 + 1480 + 2072 + 2590 + 2960 + 4144 + 5180 + 10360 + 20720 = 56544.

Nearby Examples

n	divisors count	sum σ(n)
360	24	1170
240	20	744
180	18	546
144	15	403
120	16	360
100	9	217
90	12	234
84	12	224

Related Operations for 20720

Multiples of a Number — "outward" complement of divisors
20720 Prime Factorization — decompose into prime building blocks
Find GCF of 20720 and another number
Find LCM of 20720 and another number
Is 20720 a perfect square? (odd divisor count ⇔ yes)

What Is a Divisor?

A divisor (also called a factor) of a positive integer n is any positive integer d such that n ÷ d has no remainder. In other words, d divides n evenly.

Every positive integer n has at least two divisors: 1 and n itself (with 1 being the trivial case of having only itself). Numbers with exactly 2 divisors are prime; numbers with 3 or more divisors are composite.

Why use this calculator? Beyond just listing divisors, this tool computes the sum σ(n), the count τ(n), prime factorization, divisor pairs (useful for visual learners and factoring problems), and detects whether n is a prime, a perfect square, or a perfect number.

References

Divisors Calculation Examples

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Related Calculators

Multiples of a Number — "outward" complement
Prime Factorization — product of prime divisors
Greatest Common Factor (GCF) — largest common divisor of 2+ numbers
Least Common Multiple (LCM) — smallest common multiple
Is N a Perfect Square? — odd divisor count check